Contour interpolation mechanisms can allow perception of whole objects behind occluders despite fragmental inputs. Spatial and temporal integration of visual inputs has been examined using dynamically occluded displays, and Palmer, Kellman, and Shipley (2006) suggested that a visual representation, the dynamic visual icon, maintains fragmented inputs and integrates them across spatially and temporally sparse regions. Two aspects of dynamic visual icon remain to be explored. One involves the limits on visual persistence in the dynamic visual icon, and the other is the precision or strength of interpolation. Here, we examined the temporal limits of dynamic visual icon and the strength of interpolation behind moving occluder.

A dot localization task (Guttman & Kellman, 2004) was used to reveal the strength of interpolation and temporal span of visual persistence. An illusory-contour square and a large occluder with a small window were presented to observers. The occluder rotated in front of the illusory square and the speed of rotary motion was manipulated. A small dot was presented near one of the illusory contours, and the observer made a forced-choice judgment of whether the dot appeared inside or outside the perceived illusory square. Dot position varied according to two interleaved staircase procedures. We estimated the location at which the observer perceived the interpolated contour and the precision or strength of its representation as a function of presentation cycle of inducing figures.

Results showed that error of location decreased with increasing presentation cycle, and that precision varied with the cycle. These results suggest that the temporal limits of dynamic visual icon are up to 200 ms, and that the strength of contour interpolation persists in a limited temporal span of visual processing. Further, our study indicates that the dot localization paradigm reveals the spatiotemporal and qualitative characteristics of visual representation of interpolated contour.